The present invention relates to an absorbent article such as a sanitary napkin, a pantiliner, or an incontinence pad for absorbing menstrual blood, vaginal discharge, or the like, and, specifically, relates to an absorbent article in which adhesive layers are provided to wing-like flaps, which are used so as to wrap around the crotch portion of an undergarment for fixing the absorbent article to the undergarment, and provided to seat-holding flaps to be positioned at the seat position of the undergarment posteriorly of the wing-like flaps.
Conventionally known absorbent articles such as sanitary napkins, pantiliners, vaginal discharge sheets, and incontinence pads are those each having an absorber composed of cotton-like pulp or the like interposed between a liquid-impermeable back sheet composed of a polyethylene sheet, a polyethylene laminated nonwoven fabric, or the like and a liquid-permeable front sheet composed of a nonwoven fabric, a porous plastic sheet, or the like.
In some of such absorbent articles, in order to prevent displacement when it is being worn, for example, one or more lines of adhesive layers are provided to the absorber on the skin-non-contact side (the outer surface of the liquid-impermeable back sheet), and wing-like flaps provided in a unified manner extend outward from both side edges relative to the longitudinal direction of the napkin body and are provided with adhesive layers on the skin-non-contact side. Furthermore, a pair of integral seat-holding flaps posteriorly of the wing-like flaps so as to be positioned outward from the absorber is provided with adhesive layers on the skin-non-contact side. In addition, the absorbent article individually packaged is provided with a single release paper sheet for covering all the adhesive layers.
When the absorbent article is fixed to an undergarment, the release paper sheet covering all the adhesive layers is thoroughly removed, then the absorbent article is fixed to an appropriate position of the undergarment that is pulled down, and the wing-like flaps protruding sideward are folded at the returning lines so as to wrap around the crotch portion of the undergarment and thereby to adhere to the outer surface of the crotch portion of the undergarment.
However, when the absorbent article is attached to the undergarment after the release paper sheet is thoroughly removed, since the absorber is not interposed in the wing-like flaps and the seat-holding flaps, the flaps are readily turned or bended during the attaching work. As a result, the adhesive layers provided to the flap portions adhere to the adhesive layers provided to the main body, which causes a problem that the flap portions will be broken by forcibly removing the adhesive layers from each other.
Accordingly, as described in JP-A-2007-54601 and JP-A-2007-75137, a structure for partially removing a release paper sheet when an absorbent article is fixed to an undergarment is recently employed.
That is, JP-A-2007-54601 discloses a sanitary napkin having a main body adhesive layer; a pair of wing portions and a pair of posterior flap portions that are folded to the skin-contact side of the main body at both sides relative to the longitudinal direction of the main body; a wing portion adhesive portion on the surface of each wing portion on the back sheet side for fixing the sanitary napkin to the skin-non-facing surface of clothing such as shorts; and a posterior flap portion adhesive portion on the surface of each posterior flap portion on the back sheet side for fixing the sanitary napkin to the clothing such as shorts on the skin-facing side. The sanitary napkin has a wrapping structure in which a second sheet portion covers a part of the main body adhesive layer and is folded from the posterior end of the napkin to the skin-contact side, and the protruding portion covers the wing portion adhesive portion and the posterior flap portion adhesive portion. In the wrapping structure, the napkin is set on the clothing such as shorts on the skin-facing side, maintaining the state that the wing portion adhesive portion and the posterior flap portion adhesive portion are covered with the protruding portion of the second sheet portion, and then the protruding portion is removed from both the adhesive portions, and the protruding portion of the second sheet portion is further pulled to remove it from the main body adhesive layer.
JP-A-2007-75137 discloses a packaged sanitary napkin having an anterior adhesive layer and a wing portion adhesive layer in a front half of the main body, approximately; an anterior protection sheet having a size capable of covering the adhesive layers; two lines of posterior adhesive areas, apart from each other in the width direction, near the central line in the longitudinal direction of the main body in a back half of the main body, approximately; two pairs of auxiliary posterior adhesive areas, apart from each other in the longitudinal direction, on both sides of the posterior adhesive areas; and a posterior protection sheet having a size capable of covering these adhesive layers. The sanitary napkin is set on shorts bring worn, in the state that only the anterior protection sheet is removed, and then the posterior portion is attached to the shorts by pulling the posterior protection sheet backward.